OncoAfrica

How nature’s pharmacy may be the answer to cancer

Date: 30th September 2024 | Issue #2

By Carolyn Muruthi, Ph.D.

Most of the mainstream cancer treatment options, such as chemotherapy and radiation, have shown tremendous efficacies. However, these approaches are associated with a spectrum of adverse effects, including cardiotoxicity and myelosuppression, some of which are attributable to the nonspecific nature of chemotherapeutic drugs. Chemotherapeutic drug resistance also presents an emerging obstacle, with unsatisfactory outcomes and side effects compromising the quality of life. Moreover, belligerent metastatic cancers pose a risk of relapse after remission.

The quest for effective therapies with the ability to improve survival outcomes and quality of life has increased research into natural products, most of which remains untapped. Historically revered for their medicinal properties, natural products from plants, marine organisms, and microorganisms are emerging as powerful allies in the fight against cancer. Their applications in medicine date back to ancient civilizations, with their first use reported in Mesopotamia in 2600 BC. The basis of traditional medicine systems, including Indian Ayurveda, Traditional Chinese Medicine (TCM), and indigenous knowledge systems is sculpted on the therapeutic potential of natural products, particularly those from medicinal plants.

In African communities, medicinal plants have long been integral to healthcare, largely due to their accessibility, efficacy and perceived safety. Integration of medicinal plants in cancer management within the African communities is driven by their therapeutic potential and by socio-economic factors. The high costs and limited accessibility of conventional chemotherapies pose significant barriers for many patients in these regions. In this regard, medicinal plants offer a viable alternative that aligns with local healthcare practices and economic realities. Moreover, cultural acceptance of and belief  in traditional medicine ensures a greater adherence to treatment protocols.

Medicinal plants such as Prunus africana, Withania somnifera, Carissa edulis and Moringa oleifera have been demonstrated to suppress cancer cell proliferation. The primary plant parts employed are leaves, roots, and bark, each with unique pharmacological composition. The therapeutic potential of these plants in cancer management is supported by a growing body of scientific evidence. Their anti-cancer properties have been attributed to various bioactive compounds, such as alkaloids, flavonoids, terpenoids, and phenolic compounds. These phytochemicals exhibit a range of biological activities, including antioxidant, anti-inflammatory, and cytotoxic effects, which inhibit cancer cell proliferation, induce cancer cell death, and prevent metastasis.

Modern science has validated some of the phytocompounds, leading to the discovery of several anti-tumor agents. Paclitaxel (Taxol), a diterpenoid derived from the Pacific yew tree (Taxus brevifolia) has been successfully incorporated into mainstream oncology for the treatment of ovarian, breast, and lung cancers. Taxol stabilizes cellular microtubules and inhibits cell division, making it a cornerstone in cancer treatment. Vincristine and vinblastine, alkaloids from the periwinkle plant (Catharanthus roseus), are also essential in treatment of leukemia and other malignancies. Several bioactive compounds, including roscovitine from Raphanus sativus, noscapine from Paper somniferum and pomiferin, an isoflavonoid from Maclura pomifera, are currently in clinical trials, reflecting their potential in cancer treatment.

Adopting integrative healthcare models that combine conventional medicine with complementary and alternative therapies will exert significant anti-cancer effects. For example, regular consumption of turmeric, which contains the bioactive compound curcumin with anti-inflammatory and antioxidant properties, should be encouraged. Similarly, garlic, rich in organosulfur compounds like allicin, and ginger, containing gingerol and shogaol, can be integrated into meals to exploit their anti-carcinogenic effects. Additionally, promoting daily intake of green tea, high in epigallocatechin gallate (EGCG), can provide a steady source of polyphenols that modulate cellular processes associated with cancer prevention.

Traditional cancer phytotherapy has led to the discovery of important compounds that have revolutionized cancer prevention and treatment. However, data on anticancer properties of medicinal plants is not comprehensive. Additionally, most of the anti-cancer agents from medicinal plants are yet to be subjected to clinical trials. Despite these limitations, exploration of medicinal plants for cancer treatment and bridging ancient traditional knowledge with contemporary scientific research is paramount. As multidisciplinary approaches continue to evolve, integrating advanced technologies and methodologies, the therapeutic potential of these natural compounds will become increasingly accessible. To fully realize the potential of medicinal plants in oncology, studies should focus on high throughput screening of bioactive compounds and large-scale clinical trials. By harnessing the biochemical diversity of the plant kingdom, we can uncover novel treatments that offer improved efficacy and reduced toxicity, significantly contributing to advancement of cancer therapy.